Energy storage device



FIG. 1 shows a front view of an energy storage device.

FIG. 2 is a perspective view thereof.

FIG. 3 is a side view thereof.

FIG. 4 is a top view thereof.

FIG. 5 is a bottom view thereof; and,

FIG. 6 is a rear view thereof.

The broken lines in the drawings illustrate portions of the energy storage device which form no part of the claimed design. 

CLAIM The ornamental design for an energy storage device, as shown and described. 